I have made several of these.. They are about the right size and have a couple of zipped pockets plus one you can simply reach into. It hangs in the front of your body and when I was overseas I tucked mine into the waistband of my pants. I also wore the strap under my overshirt.
Http://www.bhg.com/crafts/sewing/acc...pockets-purse/
I beefed up the attachment to the strap and made my strap out of denim rather than the embroidery thread. It's a cute bag and works well.